Production of antimicrobial bioactives of Burkholderia sp. strain RV1R2 : evaluation of activity against pathogens of clinical and agronomic importance

Muitos micro-organismos podem produzir os chamados metabólitos secundários, substâncias não-essenciais à sobrevivência celular, mas que podem garantir vantagens adaptativas a seus produtores. Distintos bioquimicamente dos produtos do metabolismo primário, esses compostos secundários geralmente executam funções externas à célula, já que são liberados para fora da mesma. Uma dessas funções é a atividade antimicrobiana, que, quando na natureza, auxilia estas células a exterminar possíveis competidores por nutrientes. O gênero Burkholderia é um dos grupos bacterianos conhecido por sua riqueza metabólica e produção de antimicrobianos naturais, com muitos compostos já descritos. A resistência a antimicrobianos na prática clínica e ambientes agrícolas já se espalhou por todo o mundo, com representantes dos reinos Monera e Fungi causando danos à saúde humana e significativas perdas econômicas. A escassez de antibióticos e pesticidas eficazes está levando à necessidade de pesquisa de novos alvos antimicrobianos, ou mesmo de drogas com múltiplos alvos de ação. Nesse cenário, os produtos naturais surgem como uma alternativa importante, já que muitos bioativos antimicrobianos já foram descritos, e os compostos de origem sintética ou semi-sintética já não tem mais ação em muitos casos. Metabólitos bacterianos podem ser uma opção para pesquisa de novos compostos de amplo espectro, que reduzam a mortalidade hospitalar ou mesmo os custos agrícolas.Many micro-organisms may produce so-called secondary metabolites, non-essential ingredients to cell survival but which can ensure adaptive advantages to their producers. Biochemically distinct from primary metabolism products, these secondary compounds generally perform functions outside the cell as they are released from it. One of these functions is antimicrobial activity, which in nature helps to exterminate possible competitors for nutrients. Genus Burkholderia is a bacterial group known for its metabolic diversity and antimicrobial production, with many compounds previously described. Antimicrobial resistance in clinical practice and agricultural environments has spread throughout the world, with representants of Monera and Fungi kingdoms causing harm to human health and economic losses. Lack of effective antibiotics and pesticides is leading to the need for research into new antimicrobial targets, or even drugs with multiple targets. In this scenario, natural products emerge as an important alternative, as many bioactive antimicrobials have been described, and compounds of synthetic or semisynthetic origin has no more action in many cases. Bacterial metabolites may be an option to search for new broad spectrum compounds, reducing hospital mortality or agricultural costs

Evolution of resistance of Klebsiella pneumoniae in Londrina University Hospital from 2000 to 2011

The present study aimed to evaluate the evolution of antibiotic resistance in clinical isolates of Klebsiella pneumoniae in the period of 2000 to 2011, at the University Hospital of Londrina (HU-UEL). A retrospective analysis of 2,318 antimicrobial susceptibility tests of K. pneumoniae was performed from a database of the Clinical Laboratory of Microbiology of the University Hospital. In the period of 2000 to 2009, the main mechanism of resistance observed to ?-lactam antimicrobials was due to the production of ESBL ?-lactamase type (?-lactamase wide spectrum), which can be verified by the increased resistance of K. pneumoniae to 3rd generation cephalosporins and cefepime. However, the first strains of K. pneumoniae carbapenemase-producing appeared in 2009, compromising the efficacy of carbapenems. The rates of resistance to ertapenem ranged from 16%, in 2005, to 40% in 2011. Another class of committed antibiotics was the fluoroquinolones; for ciprofloxacin, resistance rates ranged from 13% to 62%, in 2001 and 2011, respectively. Aminoglycosides exhibited oscillations of resistance during the period studied, reaching, in 2011, values of 56% and 30% for gentamicin and amikacin, respectively. Meanwhile, trimethoprim/ sulfamethoxazole and piperacillin/tazobactam reached about 60%, in the same period. Therefore, knowing the antimicrobial resistance of K. pneumoniae strains is essential for proper treatment of patients and adoption of appropriate measures that aims infection control, and proper use of these drugs